This Monday photo shows a pickup truck authorities say was overloaded with passengers when it veered off a highway and crashed into trees near Goliad, Texas, killing at least 13 people and injuring 10. Officials said at least 23 passengers were crammed inside the truck's cab and bed, including at least two young children. (ASSOCIATED PRESS / The Victoria Advocate, Angeli Wright)

McALLEN, Texas (AP) — With little more than photographs and fingerprints, authorities were trying to identify 14 suspected illegal immigrants who were killed when a pickup truck packed with nearly two dozen people crashed in South Texas in one of the nation’s deadliest immigrant smuggling accidents.

The victims — men, women and children — were carrying toothbrushes, toothpaste and changes of socks and underwear but no identification. Authorities said the white Ford F250 was carrying 23 immigrants from Mexico, Honduras and Guatemala when it veered off a highway and crashed into trees Sunday night.

“It’s the worst single-vehicle wreck I’ve worked in my 40 years in the funeral business,” said Adrian Fulton, a local funeral home director who picked up the 11 people who died at the scene. Fulton estimated their ages from 8 to 30, and he said Homeland Security Investigations agents came Monday to photograph and fingerprint the dead.

Federal immigration agents are looking into the human smuggling aspect of the case, while public safety authorities are investigating the cause of the crash in Goliad County, about 150 miles northeast of the Mexican border. The crash scene is less than an hour’s drive from the site of the nation’s most deadly immigrant smuggling case, where 19 immigrants died in 2003 after being placed in a sweltering trailer.

Six of those who died in Sunday’s crash were still inside the cab of the mangled vehicle and one was in the truck’s bed when emergency crews arrived at the scene, said Texas Department of Public Safety spokesman Gerald Bryant. Others were scattered on the roadway and in a ditch between the pavement and the fence line where the truck stopped.

Bryant said he saw at least two young children among the dead.

“This is the most people I’ve seen in any passenger vehicle, and I’ve been an officer for 38 years,” he said.

It is not uncommon for human traffickers to try to maximize profits by over-loading vehicles with illegal immigrants as they head north from the Texas-Mexico border. In April, nine Mexican immigrants died near the border when the teenage driver of their van crashed after fleeing Border Patrol. There were 18 people in that minivan.

In that case, six adults face a variety of federal charges and the 15-year-old driver was charged in state court with nine counts of murder.

Sunday’s accident happened around 6:30 p.m. on a rural yet busy stretch of U.S. Highway 59, which runs diagonally from the Mexican border at Laredo to Houston before turning north and running to the Canadian border. The pickup was heading north when it drove off the right side of the highway near the unincorporated community of Berclair, about 90 miles southeast of San Antonio, and struck two large trees, Bryant said.

He said it could be another week or two before the DPS accident reconstruction team finishes its work, and that investigators were trying to confirm the name of the driver, who was killed at the scene.

The truck was registered in Houston to someone other than the driver, Bryant said. A woman who answered at the address where the truck was registered said she was the daughter of the man listed at the owner. But she said they had sold the truck and it was no longer theirs. When asked when the sale took place, she hung up.

Immigration and Customs Enforcement spokesman Greg Palmore said the 11 men and three females who died included citizens of Mexico, Guatemala and Honduras.

Victor Corzo, the head of legal affairs at the Mexican consulate in San Antonio, said the only Mexican citizen involved was a 22-year-old man from Tamaulipas, the state in northern Mexico bordering Texas. Corzo said the consulate was still working to notify the man’s family.

Bryant told The Associated Press that several of the survivors of Sunday’s crash had life-threatening injuries. He did not have their official conditions but described them as “very serious.” The injured were taken to hospitals in San Antonio, Victoria and Corpus Christi.

In a statement, the Guatemalan government said that at least two Guatemalans died in the accident, a 27-year-old man and a 22-year-old woman. It said government officials “deeply lamented” their deaths and that its consulate in Houston has been in constant contact with Texas authorities.